C # MDI child forms interoperate with each other

1 usingSystem;2 usingSystem.Collections.Generic;3 usingSystem.ComponentModel;4 usingSystem.Data;5 usingSystem.Drawing;6 usingSystem.Linq;7 usingSystem.Text;8 usingSystem.Threading.Tasks;9 usingSystem.Windows.Forms;Ten  One namespaceWindowsFormsApplication1 A { -      Public Partial classForm1:form -     { the         Private stringname; -          PublicForm1 () -         { - InitializeComponent (); +         } -  +         Private voidButton1_Click (Objectsender, EventArgs e) A         { atForm2 Frm2 =NewForm2 (); -Frm2. MdiParent = This; - Frm2. Show (); -         } -  -         Private voidButton2_Click (Objectsender, EventArgs e) in         { -FORM3 Frm1 =NewForm3 (); toFrm1. MdiParent = This; + Frm1. Show (); -         } the          Public Eventaction<string>Ontext; *          Public voidTochangetext (stringobj) $         {Panax Notoginseng             if(Ontext! =NULL) -             { the ontext (obj);} +         } A         Private voidForm1_Load (Objectsender, EventArgs e) the         { +  -         } $     } $}

1 usingSystem;2 usingSystem.Collections.Generic;3 usingSystem.ComponentModel;4 usingSystem.Data;5 usingSystem.Drawing;6 usingSystem.Linq;7 usingSystem.Text;8 usingSystem.Threading.Tasks;9 usingSystem.Windows.Forms;Ten  One namespaceWindowsFormsApplication1 A { -      Public Partial classForm2:form -     { the          PublicForm2 () -         { - InitializeComponent (); -         } +  -         Private voidButton1_Click (Objectsender, EventArgs e) +         { A( This. ParentForm asFORM1). Tochangetext ("Form2 the news? "); at         } -     } -}

1 usingSystem;2 usingSystem.Collections.Generic;3 usingSystem.ComponentModel;4 usingSystem.Data;5 usingSystem.Drawing;6 usingSystem.Linq;7 usingSystem.Text;8 usingSystem.Threading.Tasks;9 usingSystem.Windows.Forms;Ten  One namespaceWindowsFormsApplication1 A { -      Public Partial classForm3:form -     { the          PublicForm3 () -         { - InitializeComponent (); -         } +  -         Private voidForm3_load (Objectsender, EventArgs e) +         { AMessageBox.Show ( This. Parentform.name); at( This. ParentForm asFORM1). Ontext + =Newaction<string>(form3_ontext); -         } -         Private voidForm3_formclosed (Objectsender, Formclosedeventargs e) -         { -( This. ParentForm asFORM1). Ontext-=Newaction<string>(form3_ontext); -         } in         voidForm3_ontext (stringobj) -         { toTextBox1.Text = textbox1.text+obj; +         } -     } the}

C # MDI child forms interoperate with each other